In cabinet making and the like it is often necessary to secure one panel perpendicularly to another during construction of the cabinet and this can be satisfactorily achieved using any one of a number of well known methods and apparatus. The choice of method and apparatus is often limited by the material being used in the panels. For example, if the material is a wood, established methods of nail and glue, or even the more elaborate methods of tongue and groove or dovetailing, will provide a joint between two panels that will last for the lifetime of the cabinet.
If the panels are made of, for example, chipboard or medium density fibreboard (MDF) established methods such as tongue and groove and dovetailing can be used only in certain circumstances and with a limited degree of success. Accordingly, a wide range of fixing devices are available to facilitate the construction of chipboard cabinets, and an example of such a device is shown in FIG. 1. Known devices of this type are commonly made from a plastics material injection moulded into the desired form which comprises a main body 10 in which screw receiving holes 12, 14, 16 are formed. Screws 18, 20 and 22 are screwed to respective walls 24, 26 and thus the cabinet may be built. Chipboard used in cabinets is normally covered in a material such as, for example, melamine, in order to provide an aesthetically pleasing finish to the board. When screws are to penetrate this material it is advantageous to pre-drill pilot or screw-receiving holes through the coating into the board in order to provide guidance for the screws, ease insertion and reduce the possibility of the board splitting as the screw is inserted. Where the board is an MDF board it is particularly important that pilot holes are drilled since MDF tends to split and delaminate otherwise. The pilot holes should ideally be full pilot holes, i.e., holes which penetrate the board at least to the depth that the screw will penetrate on insertion and which have a diameter substantially that of the minor diameter of the screw, i.e., the screw diameter less the depth of the thread.
This method of drilling full pilot holes to receive screws for fixing two panels, be they chipboard or MDF, is satisfactory in most circumstances for most jobs. However, MDF is a material which can easily be formed into strips having on at least one side a complex non-planar contour and because of this it is popularly used to provide finishing trims on cabinets and the like in, for example, a kitchen, where it is supplied in lengths of typically up to 3 meters long and is fitted along the top and bottom of a continuous rum of wall units. A problem with these trims is that the portion which will received the screw is commonly narrow in comparison with other portions, e.g., edge portions of the trim. Accordingly, it is not easy to fit the trim because of the likelihood of damage or at least weakening as the pilot hole is drilled in the narrow portion of the trim. Furthermore, because of the length of the trim, it is necessary to position such pilot holes with a high degree of accuracy since any errors in drilling are likely to be amplified along the length of the trim. Trims are usually cut ot size and drilled with pilot holes immediately prior to being fitted to the kitchen units and, as such, on-site conditions are often far from ideal for accurate drilling which further aggravates the problem.